This invention relates to means for automatically assembling and banding together the component parts of an expansion shell so that the assembly can be easily and conveniently handled, packaged and shipped.
Expansion shells, as typically used in conjunction with mine bolts, generally include a centrally-located tapered wedge, that is capable of being threaded upon a bolt, and two shell segments positioned on opposite sides of the wedge. The shell halves are joined together by means of a U-shaped metal strap. The legs of the strap are secured to the shell halves and the base of the strap passes over the top of the wedge. In operation, the shell is inserted into a hole and the bolt is threaded through the wedge to bring the end of the bolt into contact with the base of the strap. Further turning of the bolt will cause the tapered portion of the wedge to be drawn downwardly against the shell halves thereby expanding the shell halves outwardly into locking engagement with the wall of the receiving hole. An expansion shell of the type herein described is more fully disclosed in U.S. Pat. No. No. 3,248,998. Conventionally, each expansion shell is usually manufactured and shipped as an individual unit and the unit later assembled with the companion bolt. Because of its expandable construction, the shell represents an extremely loose assembly that is difficult to hold together, handle and/or package. To overcome this difficulty, resilient bands are generally placed over the two shell segments to hold the segments tightly against the wedge in a desired configuration for inserting the shell into the receiving hole.
Initially, the assembling and banding together of the expansion shell parts involved a great deal of hand labor with each of the individual operations generally being performed at a different location. As a consequence, a relatively long period of time is needed to prepare each expansion shell unit for shipment and the cost of the labor involved in producing each unit is relatively high. An automatic machine was devised by the present Applicants to eliminate much of the hand labor and time required to assemble and band together expansion shells. This machine is the subject matter of a co-pending application Ser. No. 906,823 which was filed May 17, 1978 now U.S. Pat. No. 4,178,672. The present invention incorporates some of the teachings of this prior application in a relatively simple device for assembling and banding together the component parts of an expansion shell.